1. Field of the Invention
This invention relates to a signal erasing apparatus and more particularly to an apparatus capable of continuously erasing recorded signals from a plurality of selected recording tracks formed on a rotating type record bearing medium, which has signals recorded in a plurality of circular recording tracks.
2. Description of the Prior Art
For the recording and/or reproducing apparatuses of the kind which uses, for example, a rotating type record bearing medium such as a magnetic disc or a magnetic drum, to record signals while forming recording tracks in a circular shape (in a concentric shape in the case of a disc or in an annular shape in the case of a drum) and to reproduce the signals thus recorded, it is advantageous to be able to erase the recorded signal from the medium. For erasing the whole recorded signal from a record bearing medium, use of an erasing device called a bulk eraser or a bulk erasing head is advantageous. The erasing device of this type is, however, disadvantageous in that it cannot selectively erase some specific signal recorded in one or a plurality of the recording tracks.
In such selective erasing, an erasing head which erases at once the signal recorded in one recording track on the record bearing medium (hereinafter referred to as a single track erasing head) must be used regardless of whether a recording and/or reproducing head is also used for erasing recorded signals. Where the signals of a plurality of recording tracks are to be selectively erased from the record bearing medium by means of the above-stated single track erasing device, however, the erasing operation necessitates very troublesome processes. For example, upon completion of an erasing operation on one recording track, the erasing head must be shifted to the next track and again the recorded signal erasing operation must be performed on the next track. To simplify the erasing operation, there has been proposed an erasing device which perform erasing by designating the recording track to be erased and after that subsequent tracks are automatically and continuously or consecutively erased until an erasing operation stopping or releasing member is operated to bring the erasing operation to an end. This device is advantageous in that it deletes troublesome operation processes in continuously carrying out an erasing operation on a plurality of recording tracks. However, a disadvantage of this device lies in that some recording tracks that must not be erased might be erased if the erasing stopping member is not operated on time.
The present invention is directed to the solution of the above-stated problem of the prior art device. It is therefore a principal object of the invention to provide a signal erasing apparatus which is capable of automatically and accurately erasing, in response to a simple operation thereon, signals recorded in a plurality of selected recording tracks from a rotating type record bearing medium having signals recorded thereon in a plurality of circular recording tracks.
It is another object of the invention to provide a signal erasing apparatus which is capable of erasing a signal or signals recorded in one or a plurality of selected recording tracks.
The above and further objects and features of the invention will become apparent from the following detailed description of preferred embodiments thereof taken in conjunction with the accompanying drawings.